Pneumatic tool



Sept. s, 1925. 1,553,261

, c. OVERLY v PNEUMATIC TOOL Filed Jan. '29, 1921 2 Sheets-Sheet 1 Sept.8, 1925.

C. OVERLY PNEUMATIC TOOL Filed Jan. 29, 1921 2 Sheets-Sheet GIM PatentedSept. 8, 1925.

UNITED. STATES CHARLES OVEBLY, O13, CLEVELAND, OHIO.

rnnn aA'rIe TOOL.

Application filed January 29, 1921. Serial N o. 44Q,8 8 8.

To all whom it may concern:

Be it known that I, CnIARLns OvEnLY, a citizen of the United States,residing at Cleveland, in the county of Cuyahoga and State of Ohio, haveinvented certain new and useful Improvements in Pneumatic Tools, ofwhich the following is a specification.

My invention pertains to pneumatic tools, especially riveting tools, andthe general ob- 'jects ot the invention are; first, to protect andprolong the life of the hammer or rivet set in such tools; second, torelieve the operator of recoil; and third, to keep the rivet set cool.To elucidate further, in apneumatie riveting tool wherein the piston hasa long stroke and reciprocates rapidly, it is a common experience tohave the rivet set crystallize and break at the neck or point of unionof its shank and enlarged'head because this enlarged head and theextremity of the cylinder or barrel constantly strike each otheropposite the neck under the reaction or recoil which takes placesubsequent to the piston striking the rivet set, and the shock andrecoil is also transmitted to the o aerator holding the tool. To obviatesuch troubles and disadvantages I have provided means to absorb theshock and recoil of the rivet set and cylinder, and I also utilize theair that passes or leaks from the cylinder to cool off the rivet setwhile it is in operation.

In the drawings accompanying this application, Fig. 1 is a small orreduced side view of a pneumatic riveting tool embodying my invention.Fig. 2 is an enlarged sectional view of a portion of the cylindershowing the rivet set and its retainer and shock-absorbing meansassociated therewith. Fig. 3 is a cross section on line 33, of Fig. 2.Fig. 4.- is a side view of the parts .shown in Fig. 2, excepting theretainer sleeve which is shown in section. Figs. 5, 6 and 7 illustrateseveral modified forms of the invention.

The pneumatic riveting tools in general use comprise a cylinder orbarrel 2 having a handle 3 fixed at one end and a separate hammer orrivet set 4 extending from its opposite end. A floating piston 5reciprocates very rapidly within the cylinder upon admitting compressedair, and the piston in each working stroke strikes the inner reduced end6 of rivet set 4 which in turn transmits the impact to the work in hand.The return stroke of the piston is effected by admitting air through aport 7 near the inner reentrant angle or fillet where the stem or .7

shank joins abruptly with head 8.

To overcome this ill efl'ect, I form the rivet set with a neck 9 ofsweeping curvature and without sharp reentrantfangles and interpose ashock-absorbing member between the end of cylinder 2 and head 8 of therivet set. As shown in the drawings the radius of curvature of neck 9 isapproximately the same as the diameter of the stem or shank of the rivetset. In Figs. 2 to 4:, this shockabsorbing member consists of asheet-metal collar or ring 10 of less diameter than cylinder 2 andflared and rounded at its opposite ends, the lower or outer end beingmade to conform to the curved portion of the rivet set and the upper orinner end being slotted or divided at intervals to provide curved springtongues 11 adapted to bear against the extremity of cylinder 2. In Fig.5, I show a coiled spring 12 interposed between head 8 and cylinder 2.In Fig. 6 a solid ring 13 is loosely sleeved upon the rivet set betweenhead 8 and cylinder 2. In Fig. 7, I provide a sectional retaining springsleeve 14L having an annular portion 15 of reduced diameter adapted tooccupy the space between head 8 and the end of cylinder 2, and a splitspring ring 16 encircles the sections of this sleeve to hold the saidparts together. In Figs. 1 to 4 inclusive I employ a retainer in theform of a split spring sleeve 17 having inturned flanges 18 and 19 whichextend into an annular groove 20 and beneath an annular shoulder 21 incylinder 2 and head 8, respectively. Sleeve 17 is perforated or providedwith openings 22 in its side to permit a tree escape of the air whichleaks from the cylinder around the shank of the'rivet set. This escapingair acts to cool the rivet set while in operation.

The bore or opening 23 in the outer portion of the cylinder is of largerdiameter than the piston chamber 24, which provides an annular shoulderor seat 25'where the bore and chamber meet, and the inner end of therivet set shank is reduced to provide an annular shoulder or seat 26opposite should-er or seat 25. A short coiled spring 27 confined betweensaid shoulders serves as an additional shock-absorber and protects thestriking point of the set.

As used herein the terms hammer and rivet set are synonymous, and itshould be understood that the head or hammering end may have manydifferent forms, and that different shaped hammers or rivet sets aresubstituted one for the other for different kinds of Work. Thus, some ofthe heads are short and others elongated and extended, and the hammeringends may be formed with or without cavities, and the cavities shaped toany given work. To permit such substitution the retainer or springsleeve is a detachable part of the tool, and when the parts areassembled there is a slight play between the hammer or rivet set and theretainer sleeve. 7

What I claim is:

1. A pneumatic tool or instrument, comprising a cylinder, a separatehammer having a reduced shank mounted within one end of said cylinderand a curved neck having a radius of curvature approximately the same asthe diameter of said shank, a shock-absorber associated with saidcylinder and hammer seated upon said curved neck, and a retaining sleevefor said hammer having air openings.

2. A pneumatic tool or instrument, comprising a cylinder having a pistontherein, a rivet set having a supporting shank with a curved neck ofapproximately the same radius as the diameter of said shank and withoutreentrant angles, and a shock-absorbing ring sleeved upon said neckopposite the end of said cylinder.

A pneumatic tool or instrument, comprising a rivet set having anenlarged head and a reduced shank and a curved neck uniting saidhead andshank, the relative size of the radius of curvature being approximatelythe same as the diamter of said shank, in combination with a shockabsorbing and protecting device sleeved upon said curved neck.

Signed at Cleveland, in the county of Cuyahoga, and State of Ohio, this25th day of January, 1921.

CHARLES OVERLY.

